/*      $OpenBSD: svc_simple.c,v 1.13 2015/09/01 19:54:01 deraadt Exp $ */

/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *     * Neither the name of the "Oracle America, Inc." nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* 
 * svc_simple.c
 * Simplified front end to rpc.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>
#include <sys/socket.h>
#include <netdb.h>

static struct proglst {
        char *(*p_progname)();
        int  p_prognum;
        int  p_procnum;
        xdrproc_t p_inproc, p_outproc;
        struct proglst *p_nxt;
} *proglst;
static void universal(struct svc_req *, SVCXPRT *);
static SVCXPRT *transp;

int
registerrpc(int prognum, int versnum, int procnum, char *(*progname)(),
    xdrproc_t inproc, xdrproc_t outproc)
{
        struct proglst *pl;
        
        if (procnum == NULLPROC)
                return (-1);
        if (transp == NULL) {
                transp = svcudp_create(RPC_ANYSOCK);
                if (transp == NULL)
                        return (-1);
        }
        (void) pmap_unset((u_long)prognum, (u_long)versnum);
        if (!svc_register(transp, (u_long)prognum, (u_long)versnum, 
            universal, IPPROTO_UDP))
                return (-1);
        pl = malloc(sizeof(struct proglst));
        if (pl == NULL)
                return (-1);
        pl->p_progname = progname;
        pl->p_prognum = prognum;
        pl->p_procnum = procnum;
        pl->p_inproc = inproc;
        pl->p_outproc = outproc;
        pl->p_nxt = proglst;
        proglst = pl;
        return (0);
}

static void
universal(struct svc_req *rqstp, SVCXPRT *transp)
{
        int prog, proc;
        char *outdata;
        char xdrbuf[UDPMSGSIZE];
        struct proglst *pl;

        /* 
         * enforce "procnum 0 is echo" convention
         */
        if (rqstp->rq_proc == NULLPROC) {
                if (svc_sendreply(transp, xdr_void, NULL) == FALSE)
                        exit(1);
                return;
        }
        prog = rqstp->rq_prog;
        proc = rqstp->rq_proc;
        for (pl = proglst; pl != NULL; pl = pl->p_nxt)
                if (pl->p_prognum == prog && pl->p_procnum == proc) {
                        /* decode arguments into a CLEAN buffer */
                        memset(xdrbuf, 0, sizeof(xdrbuf)); /* required ! */
                        if (!svc_getargs(transp, pl->p_inproc, xdrbuf)) {
                                svcerr_decode(transp);
                                return;
                        }
                        outdata = (*(pl->p_progname))(xdrbuf);
                        if (outdata == NULL &&
                            pl->p_outproc != xdr_void)
                                /* there was an error */
                                return;
                        if (!svc_sendreply(transp, pl->p_outproc, outdata))
                                exit(1);
                        /* free the decoded arguments */
                        (void)svc_freeargs(transp, pl->p_inproc, xdrbuf);
                        return;
                }
        exit(1);
}